This invention relates to automobile safety and, more particularly, to apparatus for testing the cornering capability of automotive vehicles to refine vehicle design and develop suspension systems which will enhance the cornering capabilities of the vehicle and prevent rollover accidents.
One cause of injuries and deaths in automotive vehicle accidents is rollover. Rollover typically occurs when the vehicle is traveling in a circular rather than a straight direction (as when the vehicle is rounding a curve). If, when traveling on this circular path, the centrifugal, inertial force becomes so large the moment on the outer wheels of the vehicle exceeds the restoring moment produced by the vehicle's weight around these same wheels, the vehicle may turn over. There are a number of factors which influence whether or not rollover occurs. See, for example STABILITY ON A CURVE by Jaroslav J. Taberek, Mechanics of Vehicles, Chapter 4. Among these are whether the vehicle has a high or low center of gravity (cg), whether the wheel tread is wide or narrow, the type of road surface (concrete, asphalt, dirt, ice), the coefficient of friction between the vehicle's tires and the road, the vehicle's suspension system, etc. Various of these factors are treated in my paper VEHICLE CORNERING STABILITY AND CG LIMITS which was presented to the Society of Allied Weight Engineers, Inc. (SAWE) at their annual conference held May 21-23, 1990.
The determination of a vehicle's cornering stability is important because of the occupants, safety. By stability is meant that the vehicle slides on a turn before it turns over. If a vehicle is sliding, the driver has the opportunity to correct the maneuver. If the vehicle tips over before it starts to slide, it is almost impossible for the driver to do anything to prevent a rollover. Consequently, if factors can be determined which promote sliding rather than tipping and these can be incorporated into the vehicle's design, the chances of rollover accidents may be greatly lessened.